Mack the Knife... '38 7up truck

Cut a bunch of little shims, pre-fit the body to the base, mark the shims, oil the inner surface of the cab, apply glue to the base where the running boards touch the front headers and the back of the grill... carefully dab some glue onto the oiled surfaces opposite the glue on the base... drop the body on the base, with a small knife combine the cab and base glue dabs,  shim, let set 48 hrs., pry / pull the body off the base, wash the body well, wash the contact surfaces on the base, paint body, when happy a light film of glue will secure it... This will only let the body/ base go back together one way ;

Because the bed sat 1/4" higher on the donar truck I made a hard foam spacer, painted the outer edges with a sharpie,  metal x red over gloss white...

"Mack the Knife" ... mock-up ... body only fits one way ;

note the saddle fuel tanks [sprue]...